This invention relates to a novel post-and-rail type of fence assembly comprised of tubular post and rail members and more particularly to a novel rail lock device for locking respective rail ends to respective posts of such a fence structure.
Post-and-rail type fences generally comprise a plurality of vertically oriented posts set into the ground at desired intervals, and one or more generally horizontal rails extending intermediate the respective spaced-apart posts. Such fencing may be constructed of various materials including wood and various metals.
Recently, however, a novel post and rail type of fence installation has been proposed utilizing tubular members of high polymer plastics materials. In this novel fence structure, the respective vertical or line posts are constructed of relatively thick-walled cylindrical tubes of a suitable high-polymer plastics material, which may advantageously be cut to desired lengths from continuously extruded material as desired. Similarly, the horizontal rail members are formed from similar material of somewhat lesser diameter and in a similar fashion so as to extend into suitable bores or openings provided therefor in the respective line posts.
The coupling together of the rails with the respective line posts requires some additional coupling or locking device.
Such a coupling or locking device should ideally be relatively simple in its construction and easy to install. However, the locking device should also ideally resist withdrawal once the rails are assembled with the line posts, to prevent accidental disassembly thereof. Hence, the locking provided by such a device or arrangement should be positive, once assembled with the rails and posts. However, again ideally, release of such a locking device, should also be relatively simple so as to permit ready removal and/or replacement of one or more fence rails when desired.
One particularly successful tubular high-polymer fence assembly of the foregoing type is available for example from CTB, Inc., P.O. Box 632, State Road 15 North, Milford, Ind. 46542. This fence assembly also provides a relatively simple bow-shaped locking device which is adapted to be flexibly compressed inwardly so as to enter the interior of the tubular fence rail member. Cooperatively, the fence rail member is provided with diametrically aligned through apertures, through which projecting end portions of the bow-shaped locking device extend when the compression or flexion thereof is released or relaxed. The locking device is provided with a pair of diametrically opposed outwardly extending arm portions which extend through the opposed through apertures of the tubular rail. Raised abutment portions are provided immediately behind these extensions or arms so as to substantially center the device within the rail with the arms projecting through the through apertures to either side. These abutment or stop portions are preferably spaced apart by an amount substantially similar to the inner diameter of the rail.
Cooperatively, the line posts are provided with circular through apertures of somewhat greater diameter than the outer diameter of the rails to receive the rails therethrough. The locking devices are therefore compressed during insertion of the rail into the line post aperture and thereafter resiliently return to extend the arms outwardly through either through aperture of the rail to thereafter resist removal thereof back through the line post aperture.
While the foregoing system has proven advantageous in many respects, there remains room for yet further improvement. In particular, there remains room for further improvement in the locking device, to assure both simplified assembly and disassembly, when desired, of the rails with respect to the line posts. Moreover, the above-described locking device has been found susceptible to failure under certain conditions of extreme stress or impact upon the fence rails, and hence there is room for further improvement in this regard as well.